Networks (e.g., local area networks, wide area networks, intranets, extranets, or the Internet) typically include a backbone that transmits a communication signal (e.g., optical, electrical, or wireless) from a source to signal converters positioned at various points along this network backbone, which convert the data signal to a form usable by electrical data signal processing circuitry.
On packet switched networks, data is transported across these backbones in data chunks known as packets. Each packet has a destination address included in the packet's header. When these packets arrive at their destination, they are reassembled and provided to the destination device.
The signal processing circuitry that receives these data packets often has multiple data ports. Each port holds a data packet in queue for processing. During processing, each data port is polled to determine if it has a data packet available for processing. If such a packet is available, the packet is processed into a form usable by the device receiving the packet. Once this packet is fully processed, the polling process is once again initiated to determine if any other port has a packet available for processing.
Packets vary in length from small packets (approximately 64 bytes) to large packets (approximately 64 kilobytes). Whenever a large packet is received by a port and subsequently processed, the polling procedure is stalled until that large packet is fully processed. All other packets waiting to be processed on any other ports will be delayed until after the processing of the large packet is completed.